First of all, apologies for the late response. I had written a response, but something happened before I sent it and the cache of my phone wasn't able to recollect my writing. I got so discouraged by this that I didn't bother with it right away.

QubesOS is interesting, I think overcomplex but needed until better systems are in place.

Well said!

Bubblejail would be an alternative that runs on normal hardware.

I hope Bubblejail will indeed reach the level of sandboxing solutions we find on e.g. mobile devices. Though, a lot of work has to be put into portals (and others) before a feat as such is achieved.

I dont know how resistant Vanadium is, it for sure doesnt send critical data, but screen size, hardware specs etc cant be not send without having no GPU acceleration and a letterboxed screen.

Would you be so kind to elaborate upon the bolded part? I'm simply unaware of the link between GPU acceleration and protection against fingerprinting.

Furthermore, just to be clear. I would like to retract my earlier statements that I've made regarding Vanadium and that were negative in nature. While there's definitely truth in the fact that it does not provide fingerprinting protection (or spoofing) like what we find on Firefox (or Brave), but they have spoken out their ambitions and intentions to improve that. It's simply that they haven't put a lot of resources yet to the cause. And this is not for saving efforts or whatsoever, but rather because they intend to offer a more robust solution (eventually). We should also not disregard that, as is, GrapheneOS does offer some level of anonymity (in combination with best practices; i.e. VPN etc) merely by the virtue of only a select number of devices being supported by GrapheneOS and thus if two users are in relatively close proximity to one another and have their VPNs enabled and use the same device with GrapheneOS, then it might be hard for others to distinguish them from one another. Finally, at least regarding this topic, I don't see them implementing letterboxing as we find on Firefox (as screen sizes are small anyways and only select number of screen sizes exist anyways, because only few devices are supported). Thus, as screen dimensions are not obfuscated, there's less need to obfuscate the GPU in the first place.

mobile browsers have limited screens size and every SOC has a different GPU basically. So if you avoid hardware rendering, you would still need to pretend to be the smallest phone comparable, and pixel density etc. may still be different.

You may find some of my thoughts in the previous paragraph.

Ungoogled Chromium is a set of patches. These should totally be applied to Secureblue chromium, but currently it is saving effords by just using Fedora chromium and a few policies

Is it strictly beneficial for security? IIRC, privacy is (unfortunately) not regarded as a design goal for secureblue.

Btw, apologies if my sentences were more convoluted and confusing than they are otherwise. Thank you for your attention and consideration!